Gaya APA

Vallen, G, K., Vallen, J, J. (2009). CHEK-IN CHECK-OUT MANAGING HOTEL OPERATIONS Eighth Edition (8). New Jersey: Pearson Education.

Gaya MLA

Vallen, Gary, K.., Vallen, Jerome, J.. "CHEK-IN CHECK-OUT MANAGING HOTEL OPERATIONS Eighth Edition". 8 New Jersey: Pearson Education, 2009. Text.